A type of equatorial mount used on short tube catadioptric telescopes in
which the telescope tube is mounted between two arms connected to a
motor drive. It does not need a counterweight to balance the tube, as
with a German equatorial mount. An equatorial wedge and field tripod are
used tilt the scope over to align it on the celestial pole for proper
tracking. Setting circles are provided to locate celestial objects by
their right ascension and declination coordinates. The r. a. setting
circle is usually driven by the scope's motor drive to move across the
sky at the same speed as the stars, following their apparent motion.
This makes fork mount setting circles more convenient to use than the
unpowered circles on most German equatorial mounts, as the latter must
be readjusted periodically to keep pace with the motion of the stars.
Photography near the north celestial pole is difficult with a fork